Dissolved Air Filtration (DAF) is an established technology more efficient than conventional clarification processes that is very effective in removing organic matter and suspended solids. DAF has been used extensively for pre-treatment in SWRO applications where algal blooms and oil spills are prevalent. With the focus on the reduction of the energy consumption in the operation of the plant and with DAF being an essential part of the SWRO process, reductions in the DAF recycle rate or saturation pressure would significantly reduce the SWRO overall energy consumption.
The technology being introduced here is able reduce the energy consumption of the pre-treatment phase of the SWRO system through the application of a proprietary ceramic plate diffuser that is able to operate at low pressure and followed by a submerged ceramic membrane filtration unit that ensures a high quality RO feed water. The energy efficient design is also highly suitable for produced water applications for water reuse and oil recovery.
The ceramic plate diffuser allows for introduction of air directly into the feed water at low pressures without a recycle stream or saturator to produce micro-bubbles (< 100 microns). The energy savings can be up to 90% compared to a conventional seawater DAF/Sand Filter system with far better effluent water quality and higher reliability..
The submerged ceramic membranes are used as an additional polishing step to produce high, constant permeate quality with low frequency backwashes. The low fouling membranes operate at average trans-membrane pressures of only 0.2 bar.
This technology can handle highly saline waters with high TSS, high Turbidity and also harsh chemical conditions. The technology is able to handle high oil in water concentrations with high recoveries of more than 95 %. The system with its automation allows for fast adaptation to rapid changes in influent quality.
The technology has two main market focuses. Firstly it is the desalination pre-treatment market and secondly it is the produced water reuse market. From the GWI, the global desalination market is expected to generate a revenue of $11,661.5 million in the base year 2015 with a growth rate of 13.6% the same year. It is expected to experience a compound annual growth rate (CAGR) of 13.1% from 2015 to 2019 and reach a revenue of $19,084.0 million in 2019.
The produced water treatment market is in the growth stage for Southeast Asia. The compound annual growth rate (CAGR) of the produced water treatment market is expected to be 5.4% from 2013 to 2018, while the market size is expected to be $357.7 million in 2018. This growth would be driven by strict discharge regulations, aging oil fields and reinjection of treated PW in EOR treatments especially in off shore applications.